Cadmium sulfide

Crystal structure
	Crystal structures of hawleyite and greenockite; __ Cd 2+ __ S 2−
General
Surname	Cadmium sulfide
other names	Cadmium monosulfide
Ratio formula	CdS
Brief description	lemon-yellow, hexagonal (α-form) or scarlet, cubic (β-form) crystals, yellow-brown as an amorphous powder
External identifiers / databases
EC number	215-147-8
ECHA InfoCard	100,013,771
PubChem	14783
Wikidata	Q179619
properties
Molar mass	144.48 g · mol -1
Physical state	firmly
density	4.82 g cm −3 (α-form); 4.50 g cm −3 (β-form);
Melting point	1750 ° C (10 M Pa ) ; decomposition from 444 ° C
Sublimation point	980 ° C
solubility	very heavy in water (1.3 mg l −1 at 18 ° C)
safety instructions
H and P phrases	H: 302-341-350-361-372-410
	P: 201-273-301 + 312 + 330-308 + 313-501
Authorization procedure under REACH	particularly worrying : carcinogenic ( CMR ), serious effects on human health are considered likely
MAK	repealed as carcinogenic
Toxicological data	7080 mg kg −1 ( LD 50 , rat , oral )
	As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Cadmium sulfide is a chemical compound made from cadmium and sulfur . It belongs to the group of II-VI compound semiconductors .

Occurrence

Cadmium sulfide occurs naturally in the form of the minerals hawleyite and greenockite .

presentation

In the laboratory, finely divided cadmium sulfide of the cubic modification is obtained by precipitating a hot acidified aqueous solution of cadmium sulfate with hydrogen sulfide:

{\ displaystyle {\ ce {CdSO4 + H2S -> CdS + H2SO4}}}

In contrast, the hexagonal modification is obtained from cadmium halide solutions by hydrogen sulfide precipitation.

properties

amorphous cadmium sulfide

Cadmium sulfide is a solid and can be present as yellow to orange-colored crystals ( wurtzite structure), as a yellow-brown powder (amorphous cadmium sulfide) or as scarlet-red cubic crystals (beta-cadmium sulfide). Cadmium sulfide is not flammable and insoluble in water. When heated in air, it decomposes with the formation of cadmium oxide and sulfur dioxide . Cadmium sulfide has the maximum sensitivity at a wavelength of 520 nm.

toxicology

Cadmium sulphide is classified by the EU list according to the GHS system in general like all soluble cadmium compounds, although the toxic potential is much lower. Water-soluble cadmium compounds are generally considered to be lung-damaging, carcinogenic, germ cell mutagenic, reprotoxic and hazardous to the aquatic environment because the soluble ions can be easily absorbed by living beings. Cadmium sulfide is not soluble in water and is relatively chemically stable. Allocation according to GHS is (currently) based on this general regulation for cadmium compounds. An individual toxicological assessment of the cadmium sulfide is currently not available. During welding or soldering work on construction materials treated with cadmium sulfide from contaminated sites, highly toxic cadmium oxide smoke is released.

History of use

Friedrich Stromeyer discovered cadmium sulfide in the laboratory in 1818. It arises from the precipitation of cadmium salts and hydrogen sulfide or sulfides . Its use as a yellow pigment has long been common. Mercury content produced a red color. Cadmium sulfide is no longer used as a pigment today, and the use of mercury is no longer permitted. For environmental reasons, the industry developed a new generation of cadmium paints for artists' paints, which are extremely chemically resistant. The cadmium yellow available today has a different chemical composition. Cadmium sulfide was previously used in semiconductor technology , photo resistors or in fluorescent materials for television tubes. It was also used as an ingredient in medicinal shampoos.

Dismantling

The degradation of cadmium sulphide on historical oil paintings takes place under the influence of light through oxidation to sulphate , as was proven by Koen Janssens . On the paintings, colorless CdSO ₄ · 2 H ₂ O and (NH ₄ ) ₂ Cd (SO ₄ ) ₂ could be found in place of the original yellow pigments .

Individual evidence

↑ ^a ^b Entry on cadmium sulfide. In: Römpp Online . Georg Thieme Verlag, accessed December 10, 2014.
↑ ^a ^b ^c ^d ^e ^f ^g ^h entry to cadmium sulfide in the GESTIS database of IFA , retrieved on July 23, 2016(JavaScript required) .
↑ Entry on cadmium sulphide in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on February 1, 2016. Manufacturers or distributors can expand the harmonized classification and labeling .
↑ Entry in the SVHC list of the European Chemicals Agency , accessed on October 18, 2015.
↑ Data sheet cadmium sulfide from AlfaAesar, accessed on May 19, 2007 ( PDF )(JavaScript required) .
↑ Georg Brauer: Cadmium sulfide . In: Handbook of Preparative Inorganic Chemistry . Ferdinand Enke Verlag, Stuttgart 1954, p. 813-814 .
↑ Cadmium pigments . In: Seilnacht's Lexicon of Dyes and Pigments
↑ Braun-Falco, O., Burg, G. (Ed.): Advances in practical dermatology and venereology, lectures of the Xth advanced training week of the Dermatological Clinic and Polyclinic of the Ludwig Maximilians University in Munich in conjunction with the Professional Association of German Dermatologists . V. from 25.-29. July 1983 . tape 10 . Springer-Verlag Berlin Heidelberg GmbH, 1983, p. 95 .
↑ G. van der Snickt, J. Dik, M. Cotte, K. Janssens, J. Jaroszewicz, W. de Nold, J. Groenewegen, L. van der Loeff: Characterization of a Degraded Cadmium Yellow (CdS) Pigment in an Oil Painting by Means of Synchrotron Radiation Based X-ray Techniques . In: Analytical Chemistry . tape 81 , no. 7 , 2009, p. 2600-2610 , doi : 10.1021 / ac802518z .

literature

I. Fiedler, M. A. Bayard: Cadmium Yellows, Oranges and Reds . In: Artists' Pigments. A Handbook of Their History and Characteristics . Vol. 1, Feller, RL (Ed.) Oxford University Press, 1986, pp. 65-108.

Web links

Wiktionary: Cadmium sulfide - explanations of meanings, word origins, synonyms, translations

Kremer Pigments: Cadmium Colors , accessed March 20, 2010.
Cadmium yellow at ColourLex

[RÖMPP-1] Entry on cadmium sulfide. In: Römpp Online . Georg Thieme Verlag, accessed December 10, 2014.

[GESTIS-2] ↑ ^a ^b ^c ^d ^e ^f ^g ^h entry to cadmium sulfide in the GESTIS database of IFA , retrieved on July 23, 2016(JavaScript required) .

[CLP_100.013.771-3] Entry on cadmium sulphide in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on February 1, 2016. Manufacturers or distributors can expand the harmonized classification and labeling .

[SVHC-4] Entry in the SVHC list of the European Chemicals Agency , accessed on October 18, 2015.

[alfa-5] Data sheet cadmium sulfide from AlfaAesar, accessed on May 19, 2007 ( PDF )(JavaScript required) .

[Brauer-6] Georg Brauer: Cadmium sulfide . In: Handbook of Preparative Inorganic Chemistry . Ferdinand Enke Verlag, Stuttgart 1954, p. 813-814 .

[7] Cadmium pigments . In: Seilnacht's Lexicon of Dyes and Pigments

[8] Braun-Falco, O., Burg, G. (Ed.): Advances in practical dermatology and venereology, lectures of the Xth advanced training week of the Dermatological Clinic and Polyclinic of the Ludwig Maximilians University in Munich in conjunction with the Professional Association of German Dermatologists . V. from 25.-29. July 1983 . tape 10 . Springer-Verlag Berlin Heidelberg GmbH, 1983, p. 95 .

[9] G. van der Snickt, J. Dik, M. Cotte, K. Janssens, J. Jaroszewicz, W. de Nold, J. Groenewegen, L. van der Loeff: Characterization of a Degraded Cadmium Yellow (CdS) Pigment in an Oil Painting by Means of Synchrotron Radiation Based X-ray Techniques . In: Analytical Chemistry . tape 81 , no. 7 , 2009, p. 2600-2610 , doi : 10.1021 / ac802518z .